feat(bookmarks): add thread expansion flags

Adds thread expansion + filtering for bookmarks, with optional ancestor branches and metadata.\n\nCo-authored-by: Klaus <[email protected]>

tests/thread-filters.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, it } from 'vitest';
+import { filterFullChain } from '../src/lib/thread-filters.js';
+import type { TweetData } from '../src/lib/twitter-client-types.js';
+
+const makeTweet = (
+  id: string,
+  createdAt: string,
+  inReplyToStatusId?: string,
+  conversationId = '1',
+): TweetData => ({
+  id,
+  text: id,
+  author: { username: 'alice', name: 'Alice' },
+  createdAt,
+  inReplyToStatusId,
+  conversationId,
+});
+
+describe('filterFullChain', () => {
+  it('returns ancestors + descendants from the bookmark only', () => {
+    const root = makeTweet('1', '2020-01-01T00:00:00Z');
+    const replyA = makeTweet('2', '2020-01-02T00:00:00Z', '1');
+    const bookmark = makeTweet('3', '2020-01-03T00:00:00Z', '2');
+    const childA = makeTweet('4', '2020-01-04T00:00:00Z', '3');
+    const childB = makeTweet('7', '2020-01-05T00:00:00Z', '4');
+    const siblingOfAncestor = makeTweet('5', '2020-01-06T00:00:00Z', '2');
+    const siblingOfRoot = makeTweet('6', '2020-01-07T00:00:00Z', '1');
+
+    const tweets = [siblingOfAncestor, childB, root, siblingOfRoot, bookmark, childA, replyA];
+
+    const result = filterFullChain(tweets, bookmark);
+    expect(result.map((tweet) => tweet.id)).toEqual(['1', '2', '3', '4', '7']);
+  });
+
+  it('includes ancestor branches when requested', () => {
+    const root = makeTweet('1', '2020-01-01T00:00:00Z');
+    const replyA = makeTweet('2', '2020-01-02T00:00:00Z', '1');
+    const bookmark = makeTweet('3', '2020-01-03T00:00:00Z', '2');
+    const childA = makeTweet('4', '2020-01-04T00:00:00Z', '3');
+    const childB = makeTweet('7', '2020-01-05T00:00:00Z', '4');
+    const siblingOfAncestor = makeTweet('5', '2020-01-06T00:00:00Z', '2');
+    const siblingOfRoot = makeTweet('6', '2020-01-07T00:00:00Z', '1');
+
+    const tweets = [siblingOfRoot, childA, replyA, childB, bookmark, root, siblingOfAncestor];
+
+    const result = filterFullChain(tweets, bookmark, { includeAncestorBranches: true });
+    expect(result.map((tweet) => tweet.id)).toEqual(['1', '2', '3', '4', '7', '5', '6']);
+  });
+});